Reactivity of 5-(Alkynyl)dibenzothiophenium Salts: Synthesis of Diynes, Vinyl Sulfones, and Phenanthrenes

Article abstract of DOI:10.1002/ejoc.202100323

The reactivity of 5-(alkynyl)dibenzothiophenium salts 1 is explored in the presence of different nucleophiles, dienes, and under photochemical conditions. Reaction with lithium acetylides affords diynes in moderate yields; while depending on the substitution pattern, the reaction with sulfinates delivers either the alkyne transfer products, alkynyl sulfones, or β-(sulfonium) vinyl sulfones through addition to the C?C triple bond. Similar behavior is observed when tosylamines are used as nucleophiles. Salts of general formula 1 also react with dienes to render the corresponding Diels-Alder cycloadducts. The vinyl sulfonium salts obtained by these routes further react with nucleophiles through a Michael addition, dibenzothiophene elimination sequence. Alternatively, they also engage in photoinduced radical cyclizations to produce substituted phenanthrenes. Attempts to use this specific addition/radical cyclization sequence for the construction of the 6a,7-dehydroaporphine skeleton present in several families of alkaloids are also described.

Full text of DOI:10.1002/ejoc.202100323

Full Papers
doi.org/10.1002/ejoc.202100323
Very Important Paper
Reactivity of 5-(Alkynyl)dibenzothiophenium Salts:
Synthesis of Diynes, Vinyl Sulfones, and Phenanthrenes
Kevin Kafuta,[a] Christian J. Rugen,[a] Tobias Heilmann,[a] Tianshu Liu,[a] Christopher Golz,[a] and
Manuel Alcarazo*[a]
In memory of Klaus Hafner.
The reactivity of 5-(alkynyl)dibenzothiophenium salts 1 is
explored in the presence of different nucleophiles, dienes, and
under photochemical conditions. Reaction with lithium acety-
lides affords diynes in moderate yields; while depending on the
substitution pattern, the reaction with sulfinates delivers either
the alkyne transfer products, alkynyl sulfones, or β-(sulfonium)
vinyl sulfones through addition to the CÀ C triple bond. Similar
behavior is observed when tosylamines are used as nucleo-
philes. Salts of general formula 1 also react with dienes to
render the corresponding Diels-Alder cycloadducts. The vinyl
sulfonium salts obtained by these routes further react with
nucleophiles through a Michael addition, dibenzothiophene
elimination sequence. Alternatively, they also engage in photo-
induced radical cyclizations to produce substituted phenan-
threnes. Attempts to use this specific addition/radical cycliza-
tion sequence for the construction of the 6a,7-
dehydroaporphine skeleton present in several families of
alkaloids are also described.
Introduction
the metal-free alkynylation of thiols, sulfonamides and activated
methylene groups.[13] Herein, we further study the reactivity of
this family of compounds in two directions. Initially, the transfer
of the alkyne moiety to additional nucleophiles such as
acetylides or sulfonates is evaluated; diynes, triynes and
alkynylsulfones are obtained from these reactions. Secondly,
the addition of acids and halogens to the CÀ C triple bond of 1
or the Diels-Alder cycloaddition between the same alkyne
moiety and dines are presented. Finally, some further reactivity
of the S-vinyl sulfonium salts thus obtained is described as well
(Scheme 1); specifically, the photocatalyzed generation of vinyl
radicals. Following this addition/radical generation/cyclization
sequence, a series of phenanthrene derivatives have been
Since their first preparation in the mid-1960s, the chemistry of
alkynyl-substituted iodonium(III) salts has been well
established.[1] These species are known to serve as efficient
alkynyl transfer reagents when reacting with nucleophiles,
which make them convenient electrophilic acetylene
synthons.[2,3] Initial examples of that reactivity were published
by Beringer,[4] and Ochiai;[5] their use in organic synthesis has
been later popularized by Zhdankin,[6] Ochiai himself,[7] Stang[8]
and Waser[9] using alkynylbenziodoxolones. Additionally, alkyn-
yl-substituted iodonium(III) salts are known precursors of vinyl
iodonium salts either via Michael type nucleophilic additions,[10]
or [4+2] cycloaddition reactions occurring at the CÀ C triple
bond.[11] The use of these I(III) derivatives however, is not always
free of inconveniences. Specifically, some of these I(III) com-
pounds are thermally unstable and show strong exothermic
decompositions on heating.[12]
Having this shortcoming in mind, we recently developed S-
alkynyl(dibenzothiophenium) salts 1, which depict an improved
safety profile and also efficiently serve as [RÀ C�C]+ synthons for
[a] Dr. K. Kafuta, C. J. Rugen, T. Heilmann, T. Liu, Dr. C. Golz,
Prof. Dr. M. Alcarazo
Institut für Organische und Biomolekulare Chemie
Georg-August-Universität Göttingen
Tammannstr 2, 37077 Göttingen, Germany
E-mail: manuel.alcarazo@chemie.uni-goettingen.de
https://www.uni-goettingen.de/en/569043.html
Supporting information for this article is available on the WWW under
https://doi.org/10.1002/ejoc.202100323
© 2021 The Authors. European Journal of Organic Chemistry published by
Wiley-VCH GmbH. This is an open access article under the terms of the
Creative Commons Attribution Non-Commercial License, which permits use,
distribution and reproduction in any medium, provided the original work is
properly cited and is not used for commercial purposes.
Scheme 1. From iodine to sulfur. General reactivity and synthetic applica-
tions of 5-(alkynyl)dibenzothiophenium salts.
Eur. J. Org. Chem. 2021, 1–12
1
© 2021 The Authors. European Journal of Organic Chemistry
published by Wiley-VCH GmbH
��
These are not the final page numbers!

Full Papers
doi.org/10.1002/ejoc.202100323
obtained from 1d. Our attempts to use this strategy for the
preparation of the 6a,7-dehydroaporphine skeleton are also
reported; however, the yields obtained are rather poor.
Results and Discussion
Reaction of 5-(alkynyl) dibenzothiophenium salts with lithi-
ated alkynes. Building upon the work of Stang, who was able
to couple alkynyl iodonium tosylates with alkynylcopper(I)
reagents to obtain asymmetric diacetylenes,[14] we submitted
1a to the reaction with terminal alkynes in the presence of a
stoichiometric amount of lithium hexamethyldisilazane
(LiHMDS). Gratifyingly, deprotonated alkynes proved to react
with 1a yielding the corresponding diynes in moderate to good
yields. In all cases, however, the formation of homocoupling
products in different amounts was detected, being the
proportion of the diynes in the mixture strongly dependent on
the substrate used. Moreover, altering the ratio of either the
sulfonium salt or the alkyne, or replacing LiHMDS with n-
butyllithium is detrimental, and causes the formation of
increased amounts of homocoupling products. Suppressing the
homocoupling however, is possible to a certain extension by
addition of CuCN (1.0 equiv.) to the reaction mixture, which
in situ generates dialkynylcuprates.[14] For example, the yield of
diyne 2b was improved from 28% to 52% using this
modification of the protocol.
The scope of the transformation is shown in Figure 1.
Unfortunately, we have not been able to establish a relation
between the electronic nature of the substrates and the
amount of homocoupling product formed. For example, both
electron- poor p-(CF3)-phenylacetylene and electron-rich p-
(OMe)-phenylacetylene performed poorly (38% and 28% yield,
respectively), while p-(I)-phenylacetylene delivered the desired
diyne in a respectable 71% yield. As expected, when the
nucleophile used is already a 1,3-diyne the corresponding TIPS-
capped triynes 2m–p are delivered in moderate to good yields.
The connectivity of 2f and 2j has been confirmed by X-ray
crystallography (see the Supporting Information).
Our previous studies on the reaction of nucleophiles with
isotope labelled 1a makes us believe that the deprotonated
alkyne most probably reacts via attack at the α-position of the
alkyne, following elimination of the dibenzothiophene unit and
concomitant regeneration of the triple bond (Figure 1).[13b]
Reaction of S-(alkynyl) dibenzothiophenium salts with
sodium sulfonates and sulfinic acids. Exposure of 1a to the
sodium salt of (hetero)aryl or alkyl sulfinates in DCM:MeOH
(1:1) cleanly resulted in the formation of alkynyl sulfones 3a–h
in moderate to excellent yields. With high probability, this
reaction proceeds via attack of the sulfinate at the α-position of
the alkyne as well, following elimination of dibenzothiophene
and regeneration of the triple bond (Figure 2). Considering the
product outcome, sulfonium salt 1a behaves as its I(III)-
analogues even if the operating reaction mechanism is not
necessarily identical.[16]
Figure 1. Substrate scope of the coupling of S-(alkynyl) sulfonium salts with
lithiated alkynes. All reagents were used in stoichiometric amounts and all
reactions were quenched after 15 min. Yields are of the isolated asymmetric
di- and triynes, in parenthesis the yields of the isolated homocoupling
products.[a] The yield of 2b was improved to 52% when 1.0 equiv. of CuCN
was added to the reaction mixture under otherwise identical conditions. X-
ray structure of 2j, ellipsoids shown at 50% probability and hydrogen atoms
omitted for clarity.[15]
In marked contrast to the transformation just described, the
reaction of sodium sulfinates with alkynyl sulfonium salt 1b,
Eur. J. Org. Chem. 2021, 1–12
www.eurjoc.org
2
© 2021 The Authors. European Journal of Organic Chemistry published
by Wiley-VCH GmbH
��
These are not the final page numbers!

Full Papers
doi.org/10.1002/ejoc.202100323
fonium salt 5a is cleanly isolated. This shows that in the
absence of an appropriate nucleophile able to attack the vinyl
sulfonium intermediate, the reaction stops after the initial
addition to the CÀ C triple bond. The absolute stereocontrol of
the addition reaction towards the Z-olefin might be considered
a hint of the assisting role of the sulfonium moiety as directing
group for the attack of the incoming nucleophile (Scheme 2b).
Moreover, the intermediate ylide can be trapped with electro-
philes other than a proton. For example, when the reaction of
1b and sodium benzenesulfinate is carried out in the presence
of excess of naphtho[1,8-cd][1,2]dithiole without protic solvent,
then 2-methylenenaphtho[1,8-de][1,3]dithiine
6 is obtained
(Scheme 2c). The formation of this product can be explained via
a sequence starting with the β-attack of the sulfonate to 1b,
trapping of the ylidic intermediate by the disulfide, intra-
molecular Michael addition of the in situ generated sulfide
moiety to the vinyl sulfonium fragment and final elimination of
dibenzothiophene.
The reactivity of salt 5a has been further examined; a set of
ten different reactions involving nucleophiles of diverse nature
that include CÀ , SÀ , NÀ , PÀ , OÀ and halogen-based ones, are
shown in Scheme 3. Given the excellent leaving group proper-
ties of the dibenzothiophene unit, all nucleophiles tested are
able to smoothly react with 5a and replace this moiety
affording the desired β-substituted vinyl sulfone with moderate
to excellent yields. The substitution reaction takes place with
retention of the Z-configuration of the olefin in most of the
cases, as could be confirmed either by NOE experiments or
comparison with literature data.[17a] This is remarkable since the
Figure 2. Substrate scope of the coupling of S-(alkynyl) sulfonium salts with
sodium sulfinates. Yields are of the isolated products. X-ray structure of 3e;
ellipsoids shown at 50% probability and hydrogen atoms are omitted for
clarity.[15]
which has a terminal Ph group at the alkyne moiety, does not
deliver alkynyl sulfones but β-ethoxy-(Z)-vinylsulfone 4a (Sche-
me 2a). This different reactivity mode has been already
described for selenonium and iodonium salts and reveals the
preference of alkynyl sulfonium salts to suffer the attack of the
nucleophile at the alkyne β-position when steric factors do
allow it.[17] Moreover, when 1b was made react with benzene-
sulfinic acid in DCM:t-BuOH, (10:1) the (Z)-β-sulfonylalkenylsul-
Scheme 3. Synthesis and reactivity (Z)-β-sulfonylalkenylsulfonium salt 5a; a)
1,3-diketone (1.0 equiv.), Cs2CO3 (1.0 equiv.), CH2Cl2, rt, 12 h; b) TsNa
(1.0 equiv.), CH2Cl2 :t-BuOH (1:1), rt, 12 h; c) NaSCN (1.1 equiv.), CH2Cl2/t-
BuOH (1:1), rt, 12 h; d) PPh3 (1.2 equiv.), CH2Cl2, rt, 12 h; e) o-Br-thiophenol
(1.0 equiv.), Cs2CO3, CH2Cl2, rt, 12 h; f) p-cresol (1.0 equiv.), Cs2CO3 (1.0 equiv.),
CH2Cl2, rt, 12 h; g) LiHMDS (1.0 equiv), p-F-(C6H4)À C�CH (1.0 equiv), CH2Cl2, rt,
12 h; h) KF (1.2 equiv.), CH2Cl2 :t-BuOH (1:1), rt, 12 h; i) Bu4NBr (1.0 equiv.),
CH2Cl2, rt, 12 h; j) MeNHTs (1.2 equiv.), Cs2CO3 (1.2 equiv.), CH2Cl2, rt, 12 h.
Scheme 2. Synthesis of (Z)-β-sulfonylalkenylsulfonium salt 5a and plausible
mechanism for its formation. X-ray structures of 5a and 6; ellipsoids shown
at 50% probability, anion in 5a and hydrogen atoms removed for clarity.[15]
Eur. J. Org. Chem. 2021, 1–12
www.eurjoc.org
3
© 2021 The Authors. European Journal of Organic Chemistry published
by Wiley-VCH GmbH
��
These are not the final page numbers!

Full Papers
doi.org/10.1002/ejoc.202100323
Z- products obtained are often the thermodynamically less
ingly, alkynyl sulfonium salts also undergo smoothly Diels-Alder
cycloaddition with cyclopentadiene to deliver the correspond-
ing bicyclic cyclohexadiene 12 in good yield. This reactivity is
again parallel to that already observed for alkynyl-substituted
hypervalent I(III) reagents.[19]
stable ones. Olefin isomerization could only be detected for
compounds 4f and 4h and even in these cases it occurred in
moderate extent (Scheme 3). A direct attack of the nucleophile
to the sulfonium moiety in 5a, followed by reductive coupling
between the nucleophile and the vinyl moiety provides a
feasible explanation for this stereochemical outcome; however,
a Michael-type addition of the nucleophile to the α-carbon of
the vinyl moiety follow by elimination of dibenzothiophene
cannot be completely excluded, in particular for those cases
where some isomerization is detected.
Reaction of 5-(alkynyl) dibenzothiophenium salts with
halogens and dienes. The straightforward addition of sulfonic
acids to 1b made us believe that β-halovinyl sulfonium salts
and α,β-dihalovinyl sulfonium salts might also be accessed,
respectively, via addition of HX or X2 (X=halogen) to the
corresponding 5-(alkynyl)dibenzothiophenium salts 1. These
reactions actually work efficiently, and the desired mono- and
dihalogenated products 7–11 have been obtained in good to
excellent yields (Scheme 4). The atom connectivity of com-
pounds 8 and 11 has been subsequently confirmed by X-ray
analysis.
Additionally, having in mind the ability of sulfonium salts to
generate organic radicals via mesolitic SÀ C bond cleavage after
accepting one electron, we set up to study whether appropri-
ately designed alkenyl-substituted sulfonium salts could be
used for the assembly of phenanthrene skeletons via radical
induced cyclization.[20] Hence, we prepared 13 and 15 from 1d
following the methods herein reported, and submitted these
products to photochemically induced one electron reduction
using very similar reaction conditions to those recently
developed by Procter and coworkers for the coupling between
the exo-aryl group of dibenzothiophenium salts and non-
functionalized (hetero)arenes[21]. To our delight, the proposed
transformation took place smoothly and the expected phenan-
threnes 14 and 16 were obtained, albeit with moderate yields
(Scheme 5).[22]
Synthesis of the 6a,7-dihydroaporphine scaffold. Finally,
we decided to explore whether the just described addition/
cyclisation protocol would be useful for the synthesis of the
The formation of 7, 8 and 10 is diastero- and regioselective
and probably follows the mechanism already described in
Scheme 2b. The synthetic potential of these products is obvious
if one considers the known differences in reactivity of alkenyl
chlorides, bromides, iodides, and sulfonium salts.[18] Interest-
6a,7-dihydroaporphine core A,
a tetracyclic amine which
constitutes the skeleton of dozens of alkaloids such as for
example Artabotrine (17),[23] (À )-6a,7-dehydrofloripavidine
(18),[24] or Telisatin B (19),[25] among others.[26] We envisaged that
if access to sulfonium salts of general formula B could be
provided, then, intramolecular hydroamination of the triple
bond followed by cyclization of the photochemically generated
vinyl radical should deliver the desired tetracycle (Scheme 6).
In order to evaluate the feasibility of the synthetic strategy
just presented, known tosylamide 20 was chosen as appropriate
starting material. Regioselective bromination and subsequent
iodination of this compound following a protocol already
described for similar substrates affords compound 21.[27]
Sonogahira reaction with TIPS-protected acetylene selectively
delivered the corresponding alkyne 22, which was subsequently
Scheme 4. Additions to the triple bond of 1b–c; a) 2 M HCl in Et2O
(1.5 equiv.), CH2Cl2, rt, 12 h; b) ICl (1.2 equiv.), CH2Cl2, rt, 12 h; c) Br2 1.0
Scheme 5. Phenanthrene syntheses via photochemical methods; a) cyclo-
°
°
(equiv.), CH2Cl2, rt, 12 h; d) cyclopentadiene (5.0 equiv.), CH3CN, 100 C, μW,
pentadiene (5.0 equiv.), CH3CN, μW, 100 C, 3 h; b) Cs2CO3 (1.1 equiv.),
[Ru(bpy)3]Cl2 ·6 H2O (2 mol%), CH3CN, Blue LED (28 W), rt, 16 h.; c) PhSO2H
(2.0 equiv.), CH2Cl2/t-BuOH (8:1), rt, 12 h.
2 h. X-ray structures of 8 and 11; hydrogen atoms removed for clarity and
ellipsoids shown at 50% probability.[15]
Eur. J. Org. Chem. 2021, 1–12
www.eurjoc.org
4
© 2021 The Authors. European Journal of Organic Chemistry published
by Wiley-VCH GmbH
��
These are not the final page numbers!

Full Papers
doi.org/10.1002/ejoc.202100323
Scheme 6. Synthetic strategy for the synthesis of the 6a,7-dihydroaporphine
scaffold.
cross-coupled with phenylboronic acid to produce biphenyl
derivative 23. Unfortunately, all attempts to install the sulfo-
nium moiety directly in 23 were unsuccessful probably due to
the steric demand of the TIPS group. For this reason, 23 was
treated with TBAF to afford the terminal acetylene 24 in
excellent yield as a crystalline material. The atom connectivity
of this product was established by X-ray crystallography
(Scheme 7). Treatment of 24 with activated dibenzothiophene
S-oxide finally afforded a sulfonium salt, which is not the
expected alkynyl substituted one but already the result of the
intramolecular addition of the sulfonamide moiety to the alkyne
fragment 25 (Scheme 7). The stage was then set for the key
photocyclization, which occurred under the optimized condi-
tions already identified for the preparation of 14 and 16.
Unfortunately, though the desired N-tosyl dihydroaporphine 26
could be obtained from that experiment, the isolated yield is
rather poor. In fact, the main product identified from the
mixture is azulene 27; a structure that has been proposed to
derive from the insertion of an in situ generated vinyl carbene
into the proximal CÀ C bond of the adjacent phenyl rest.[28]
Treatment of 25 with strong bases such as KH does not solve
the selectivity problem. In fact, complex reaction mixtures are
obtained from which 26 is again isolated in low yields. From a
crystal formed from the crude reaction mixture, we could also
identify 28 as side product by X-ray diffraction; however, we
Scheme 7. Studies towards the synthesis of the 6a,7-dihydroaporphine
°
°
scaffold; a) NBS, 60 C, 16 h; b) NIS, TFA, CH3CN, μW 110 C, 16 h.; c) TIPS-
°
acetylene, Pd(PPh3)2Cl2, CuI, NEt3, THF, μW 90 C, 60 h.; d) PhB(OH)2,
°
Pd(PPh3)2Cl2, Na2CO3, DME/H2O, μW 120 C, 26 h.; e) TBAF, THF, rt, 2 h.; f)
°
°
dibenzothiophene-S-oxide, Tf2O, CH2Cl2, À 50 C!À 20 C, 16 h.; g) [Ru-
(bipy)3]2 ·6H2O (3 mol%), blue LEDs, Cs2CO3 (1.4 equiv.), CH3CN; h) KH
(3.0 equiv.), KOt-Bu (10 mol%). X-ray of 24 drawn at 50% probability level;
only amide and ethynyl protons shown.[15]
initial adducts into Z-configured vinyl sulfones and phenan-
threnes is also described herein. Considering the multitude of
products that might be gained following these protocols, we do
believe that the chemistry of 5-alkynyl sulfonium salts shows a
vast synthetic potential, which is still under study in our
laboratory.
were not able to isolate an analytically pure sample of that Experimental Section
enamine.
General experimental details: All reactions were carried out using
pre-dried glassware under nitrogen atmosphere unless otherwise
stated. Dry and degassed solvents (THF, dichloromethane, toluene,
n-pentane, diethyl ether) were obtained with the MBraun Solvent
Purification System (MB-SPS-800) or by distillation over appropriate
drying agents and stored under nitrogen atmosphere. Flash
chromatography was performed either on Merck 60 (40–63 μm) or
Macherey-Nagel 60 (40–63 μm) silica gel. Thin-layer chromatogra-
phy (TLC) analyses were performed using polygram SIL G/UV254
from Macherey-Nagel and visualized by UV irradiation and/or
phosphomolybdic acid, KMnO4 or p-anisaldehyde dip. All commer-
cially available products (Acros Organics, ABCR, Alfa Aesar, Sigma
Conclusion
We have further evaluated the reactivity of 5-(alkynyl)
dibenzothiophenium salts, which are easily prepared from the
reaction of dibenzothiophene S-oxide with TMS-capped or even
free alkynes. While TIPS-substituted salts react with nucleophiles
transferring the alkyne moiety; aryl substituted salts preferen-
tially suffer addition reactions to the CÀ C triple bond to deliver
5-vinyl sulfonium species. The further transformation of these
Eur. J. Org. Chem. 2021, 1–12
www.eurjoc.org
5
© 2021 The Authors. European Journal of Organic Chemistry published
by Wiley-VCH GmbH
��
These are not the final page numbers!

Full Papers
doi.org/10.1002/ejoc.202100323
1
Aldrich, Fluorochem, TCI) were used as received. Compounds 1a,
1b and 1c were synthesized according to known procedures.[13]
chromatography (gradient hexanes!hexanes:EtOAc 1:1). H NMR
(400 MHz, CDCl3): δ=7.98 (d, J=8.3 Hz, 2H), 7.75 (d, J=8.3 Hz, 2H),
7.58 (t, J=7.5 Hz, 1H), 7.47–7.32 (m, 5H), 7.29–7.24 (m, 2H), 7.22–
7.18 (m, 2H), 6.87 (s, 1H), 2.47 (s, 3H) ppm. 13C NMR (101 MHz,
CDCl3): δ=151.9, 145.3, 141.4, 138.6, 138.4, 134.4, 132.7, 130.4,
General procedure for the synthesis of compounds 2a–2p
~
129.9, 129.8, 129.4, 129.1, 128.6, 128.5, 21.9 ppm. IR (neat): u=
The corresponding 1-alkyne or 1,3 diyne (0.2 mmol, 1.0 equiv.) was
dissolved in anhydrous DCM (2 mL, 0.1 M) under inert atmosphere
and LiHMDS (0.2 mL of a 1 M solution in THF, 0.2 mmol, 1.0 equiv.)
3060, 3011, 1595, 1325, 1148, 1079, 907, 726, 670, 563 cmÀ 1. HRMS
(ESI) m/z calcd for C21H19O4S2 [M+H]+: 399.0719; found: 399.0704.
+
°
was added at À 78 C under stirring. The reaction mixture was
(Z)-[(1-Phenyl-2-thiocyanatovinyl)sulfonyl]benzene 4d: Salt 5a
(115.3 mg, 0.2 mmol, 1 equiv.) was added in one portion to a stirred
solution of NaSCN (19.5 mg, 0.24 mmol, 1.2 equiv.) in a mixture of
CH2Cl2 (1 mL) and t-BuOH (1 mL). The reaction mixture was stirred
at r.t. for 12 h. Column chromatography (gradient hexanes!
hexanes:EtOAc 4:1) of the reaction mixture thus obtained afforded
pure 4d (43.4 mg, 0.144 mmol, 72%) as a white solid. 1H NMR
(400 MHz, CDCl3): δ=7.65 (dd, J=8.4, 1.2 Hz, 2H), 7.60 (t, J=7.5 Hz,
1H), 7.47–7.42 (m, 2H), 7.37 (t, J=7.4 Hz, 1H), 7.29 (t, J=7.6 Hz, 2H),
7.22–7.18 (m, 2H), 6.99 (s, 1H) ppm. 13C NMR (101 MHz, CDCl3): δ=
142.5, 138.1, 134.6, 131.7, 131.2, 130.2, 129.5, 129.4, 128.8, 128.1,
°
allowed to warm up to 0 C and stirred for additional 5 min.
°
Successively, it was cooled back to À 78 C, and 1a (103 mg,
0.2 mmol, 1.0 equiv.) was added in one portion. Then, the reaction
mixture was allowed to warm up to r.t. and stirred for an additional
10 min. Finally, the reaction was quenched with water and
extracted with EtOAc (3×5 mL). The desired products were
obtained after purification by column chromatography using
pentane as eluent. As representative example the spectroscopic
1
characterization of 2e is listed: H NMR (300 MHz, CDCl3): δ=8.73
(s, 1H), 8.56 (d, J=4.2 Hz, 1H), 7.78 (d, J=7.9 Hz, 1H), 7.29–7.22 (m,
1H), 1.11 (s, 21H). 13C NMR (125 MHz, CDCl3): δ=153.5, 149.3, 139.6,
~
111.9 ppm. IR (neat): u=3030, 1737, 1367, 1306, 1210, 1146, 1084,
+
753, 684, 651 cmÀ 1. HRMS (ESI) m/z calcd for C15H11NNaO2S2 [M+
~
123.1, 119.2, 89.9, 89.0, 78.0, 72.2, 18.7, 11.4 ppm. IR (neat): u=
2940, 2862, 2204, 2106, 1462, 1404, 996, 882, 659, 602 cmÀ 1. HRMS
(EI) m/z calcd for C18H25NSi+ [M]+: 283.1751; found: 283.1750. See
the SI for the characterization of all other dienes and trienes.
Na]+: 324.0123; found: 324.0122.
(Z)-Triphenyl[2-phenyl-2-(phenylsulfonyl)vinyl]phosphonium tri-
fluoromethanesulfonate 4e: A Schlenk flask equipped with a
stirring bar was charged with 5a (115.3 mg, 0.2 mmol, 1 equiv.) and
Ph3P (63 mg, 0.24 mmol, 1.2 equiv.). Both reactants were dissolved
in CH2Cl2 (2 mL) and the reaction mixture was stirred at room
temperature for 12 h. After this the solvent was evaporated and
diethyl ether (10 mL) was added to precipitate the salt, which was
filtered off, washed once more with diethyl ether (10 mL) and dried
in vacuo. Salt 4e (83.8 mg, 0.128 mmol, 64%) was obtained as a
General procedure for the synthesis of compounds 3a–3h
Sulfonium salt 1a (103 mg, 0.2 mmol, 1.0 equiv.) and the corre-
sponding sulfinate (0.24 mmol, 1.2 equiv.) were dissolved in
DCM:MeOH 1:1 (5 mL), and the reaction mixture was stirred for
30 min at r.t. Upon completion of the reaction (monitoring via TLC),
pentane (5 mL) was added, and the reaction mixture was trans-
ferred directly to a pre-wetted (hexane) silica column and eluted
with the same solvent to afford the desired products. As
representative example the spectroscopic characterization of 3g is
listed: 1H NMR (400 MHz, CDCl3): δ=8.33–8.26 (m, 1H), 7.99–7.92
(m, 1H), 7.87–7.79 (m, 2H), 1.20–1.06 (m, 21H) ppm. 13C NMR
(101 MHz, CDCl3): δ=148.3, 135.4, 135.2, 133.1, 131.0, 125.5, 102.6,
1
white solid. H NMR (400 MHz, CD3CN): δ=8.54 (d, J=8.6 Hz, 2H),
8.31 (d, J=7.9 Hz, 2H), 7.98 (t, J=7.7 Hz, 2H), 7.95–7.88 (m, 5H),
7.87–7.82 (m, 2H), 7.77 (d, J=7.5 Hz, 3H), 7.64–7.59 (m, 3H), 7.46–
7.38 (m, 2H), 7.31 (d, J=4.6 Hz, 4H), 6.85 (s, 1H) ppm. 31P NMR
(162 MHz, CD3CN): δ=16 ppm. 13C NMR (101 MHz, CD3CN): δ=
2
4
166.5, (d, J P-C =3.6 Hz), 157.3, 141.0, 136.8, 135.8, 135.7 (d, J
=
P-C
3.2 Hz), 135.0 (d, 1J P-C =10.8 Hz), 134.6 (d, 4J P-C =10.7 Hz), 132.9,
132.4, 131.7, 131.3 (d, 1J P-C =13.3 Hz), 131.0 (d, 2J P-C =13.5 Hz),
~
99.3, 18.5, 11.1 ppm. IR (ATR): u=2948, 2867, 2360, 2340, 2124,
1542, 1336, 1159, 803, 575 cmÀ 1
. HRMS (ESI) m/z calcd for
130.8, 130.2, 130.2, 129.7 (d, 2JP-C =13.7 Hz), 129.6 (d, 2J
=
=
P-C
C17H26NO4SSi+ [M+H]+: 368.1346; found: 368.1342. See the SI for
14.0 Hz), 127.9, 125.3, 122.1 (q, 1JC-F =321 Hz), 122.0 (d, JP-C
1
the characterization of all other alkynyl sulfones.
~
93.7 Hz), 121.3 ppm. IR (ATR): u=3730, 3628, 2266, 1648, 1255,
1148, 1029, 686, 636, 515 cmÀ 1
. HRMS (ESI) m/z calcd for
(Z)-2-Phenyl-2-[2-phenyl-2-(phenylsulfonyl)vinyl]-1H-indene-
1,3(2H)-dione 4b: A mixture of 5a (115.3 mg, 0.2 mmol, 1.0 equiv.),
Cs2CO3 (65.2 mg, 0.2 mmol, 1.0 equiv.) and 1,3-indandione (29.2 mg,
0.2 mmol, 1.0 equiv.) in CH2Cl2 (2 mL) was stirred at room temper-
ature for 12 h and then directly transferred to a pre-wetted column
(hexane). Pure 4b (80.8 mg, 173.9 μmol, 87%) was obtained as an
orange oil by column chromatography (gradient hexanes!hexane-
C32H26O2PS+ [MÀ OTf]+: 505.1386; found: 505.1385.
(E/Z)-(2-Bromophenyl)[2-phenyl-2-(phenylsulfonyl)vinyl] sulfane
4f: A suspension of 5a (115.3 mg, 0.2 mmol, 1.0 equiv.), Cs2CO3
(65.2 mg, 0.2 mmol, 1.0 equiv.) and 2-bromobenzenethiol (37.8 mg,
0.2 mmol, 1.0 equiv.) in CH2Cl2 (2 mL) was stirred at r.t. for 12 h and
then directly transferred to a pre-wetted chromatography column
(hexanes). Pure 4f (77.6 mg, 179.8 μmol, 90%) was obtained as a
white solid (mixture of Z/E isomers (5:1)) after column chromatog-
1
s:EtOAc 4:1). H NMR (400 MHz, CDCl3): δ=7.90 (s, 1H), 7.53 (t, J=
7.2 Hz, 2H), 7.49–7.45 (m, 2H), 7.45–7.29 (m, 12H), 7.27–7.23 (m, 2H),
7.16 (d, J=7.2 Hz, 1H) ppm. 13C NMR (101 MHz, CDCl3): δ=192.8,
168.2, 150.7, 139.1, 138.4, 133.51, 133.45, 130.8, 130.6, 130.6, 129.6,
129.6 (2 overlapped 13C signals), 128.9, 128.8, 128.6, 128.5, 128.4,
1
raphy (gradient hexanes!hexanes:EtOAc 1:1). H NMR (400 MHz,
CDCl3): δ=7.85 (dd, J=8.4, 1.2 Hz, 2H), 7.67–7.61 (dt J=1.4, 8.0 Hz,
2H), 7.59–7.52 (m, 1H), 7.47–7.42 (m, 2H), 7.41–7.26 (m, 4H), 7.26–
7.19 (m, 3H), 6.98 (s, 1H) ppm. 13C NMR (101 MHz, CDCl3): δ=144.7,
140.4, 136.3, 135.7, 134.4, 134.3, 134.0, 133.6, 130.6, 130.3, 130.0,
~
128.3, 128.1, 127.5, 122.8, 119.4, 116.9 ppm. IR (neat): u=3725,
3626, 1715, 1378, 1308, 1204, 1146, 1082, 689, 646 cmÀ 1. HRMS
(ESI) m/z calcd for C29H20NaO4S+ [M+Na]+: 487.0975; found:
487.0975.
~
129.0, 128.8, 128.44, 128.39, 127.8 ppm. IR (ATR): u=3728, 3626,
1737, 1557, 1447, 1306, 1146, 1084, 753, 664 cmÀ 1. HRMS (ESI) m/z
+
calcd for C20H16O2S2 [M+H]+: 430.9770; found: 430.9769.
(Z)-1-Methyl-4-{[2-phenyl-2-(phenylsulfonyl)vinyl]sulfonyl}
benzene 4c: Compound 5a (115.3 mg, 0.2 mmol, 1.0 equiv.) and
sodium p-tolylsulfinate (35.6 mg, 0.2 mmol, 1.0 equiv.) were dis-
solved in CH2Cl2/t-BuOH 1:1 (2 mL) and the reaction mixture was
stirred at room temperature for 12 h. Pure 4c (60.6 mg,
0.152 mmol, 76%) was obtained as a colorless oil by column
(Z)-1-Methyl-4-{[2-phenyl-2-(phenylsulfonyl)vinyl]oxy}
benzene
4g: A suspension of 5a (115.3 mg, 0.2 mmol, 1.0 equiv.), Cs2CO3
(65.2 mg, 0.2 mmol, 1.0 equiv.) and p-cresol (21.6 mg, 0.2 mmol,
1.0 equiv.) was stirred in CH2Cl2 (2 mL) at r.t. for 12 h. Then, the
solvents were evaporated, and the residue was charged into a pre-
Eur. J. Org. Chem. 2021, 1–12
www.eurjoc.org
6
© 2021 The Authors. European Journal of Organic Chemistry published
by Wiley-VCH GmbH
��
These are not the final page numbers!

Full Papers
doi.org/10.1002/ejoc.202100323
wetted chromatography column (hexanes). Pure 4g (64.5 mg,
rated, and diethyl ether (2×40 mL) was added to wash the salt,
0.184 mmol, 92%) was obtained as a white solid by column
which was finally dried in vacuo. Product 5a was obtained as a
1
beige solid (1.113 g, 1.93 mmol, 83%); m.p.: 184–185 C. 1H NMR
°
chromatography (gradient hexanes!hexanes:EtOAc 1:1). H NMR
(400 MHz, CDCl3): δ=7.98 (dd, J=8.4, 1.3 Hz, 2H), 7.61–7.56 (m, 1H),
7.52–7.46 (m, 2H), 7.43–7.36 (m, 5H), 7.11 (d, J=8.1 Hz, 2H), 6.90 (s,
1H), 6.83 (d, J=8.6 Hz, 2H), 2.31 (s, 3H) ppm. 13C NMR (101 MHz,
CDCl3): δ=154.4, 150.3, 142.5, 134.9, 133.1, 131.3, 131.0, 130.4,
(400 MHz, CD3CN) δ=8.52 (d, J=8.2 Hz, 2H), 8.31 (d, J=7.8 Hz, 2H),
7.98 (t, J=7.7 Hz, 2H), 7.93 (d, J=8.5 Hz, 2H), 7.87–7.83 (m, 2H), 7.79
(t, J=7.5 Hz, 1H), 7.64–7.59 (m, 2H), 7.43 (t, J=8.7 Hz, 1H), 7.34–7.29
(m, 4H), 6.84 (s, 1H) ppm. 13C NMR (101 MHz, CD3CN): δ=157.5,
141.1, 136.9, 136.3, 135.8, 132.9, 132.5, 131.7, 130.9, 130.6, 130.30,
~
129.0, 128.8, 128.5, 128.1, 125.9, 117.2, 20.8 ppm. IR (ATR): u=3080,
2923, 1632, 1600, 1504, 1224, 1141, 726, 686, 574 cmÀ 1. HRMS (ESI)
m/z calcd for C21H18NaO3S+ [M+Na]+: 373.0869; found: 373.0863.
130.28, 129.8, 129.6, 127.9, 125.4, 122.1 (q, JC-F =321 Hz) ppm. IR
1
~
(ATR): u=2360, 2337, 1447, 1309, 1253, 1224, 1148, 1028, 759,
+
635 cmÀ 1
.
HRMS (ESI) m/z calcd for C26H19O2S2 [MÀ OTf]+:
(Z)-[2-Fluoro-1-(phenylsulfonyl)vinyl]benzene 4i: 5a (115.3 mg,
0.2 mmol, 1 equiv.) was added in one portion to a solution of KF
(13.9 mg, 0.24 mmol, 1.2 equiv.) in CH2Cl2 (1 mL) and t-BuOH (1 mL).
The reaction mixture was stirred for 12 h at r. t. Then, the solvents
were evaporated, and the residue was charged into a pre-wetted
chromatography column (hexanes). Pure product 4i (21.0 mg,
427.0821; found: 427.0821.
2-[Phenyl(phenylsulfonyl)methylene]naphtho[1,8-de][1,3] dithiine
6: 1b (87.0 mg, 0.20 mmol, 1.0 equiv.), naphtho[1,8-cd][1,2]dithiole
(76.1 mg, 0.4 mmol, 2.0 equiv.), 15-C-5 (100.1 mg, 90 μL, 0.45 mmol,
2.25 equiv.) and sodium phenylsulfinate (49.2 mg, 0.3 mmol,
1.5 equiv.) were dissolved in DCM (3 mL) and the mixture stirred at
r.t. under nitrogen overnight. Then, the solvents were evaporated
and the residue charged into a pre-wetted silica column (hexanes).
Pure 6 (36.3 mg, 83.9 μmol, 42%) was obtained as a white solid
after column chromatography (gradient hexanes!hexanes:EtOAc
8:2). 1H NMR (400 MHz, CDCl3): δ=7.83 (dd, J=8.4, 1.2 Hz, 2H),
7.63 (d, J=8.1 Hz, 1H), 7.61–7.55 (m, 2H), 7.50 (d, J=6.2 Hz, 1H),
7.48–7.35 (m, 6H), 7.30–7.26 (m, 1H), 7.10 (dd, J=11.3, 7.2 Hz, 3H)
ppm. 13C NMR (101 MHz, CDCl3): δ=143.3, 140.7, 134.3, 133.5,
133.1, 131.8, 130.8, 129.6, 128.9, 128.8, 128.3, 128.2, 128.1, 127.5,
80 μmol, 40%) was obtained as
a white solid by column
1
chromatography (gradient hexanes!hexanes:EtOAc 4:1). H NMR
(400 MHz, CDCl3): δ=7.84 (d, J=7.5 Hz, 2H), 7.62 (t, J=7.5 Hz, 1H),
7.50 (t, J=7.8 Hz, 2H), 7.41 (d, J=7.3 Hz, 1H), 7.35 (t, J=7.4 Hz, 2H),
7.29–7.25 (m, 2H), 6.83 (d, J=78.5 Hz, 1H) ppm. 19F NMR (376 MHz,
CDCl3): δ=À 101.96 (d, J=78.6 Hz) ppm. 13C NMR (101 MHz, CDCl3):
δ=152.8 (d, 1JC-F =292.7 Hz), 140.8, 133.9, 131.0 (d, 2JC-F =3.2 Hz),
130.2, 130.2, 129.9, 129.2, 128.7, 128.1 (d, 3JC-F =1.1 Hz) ppm. IR
~
(neat): u=3728, 3628, 1648, 1325, 1180, 1135, 1079, 732, 667,
553 cmÀ 1. HRMS (ESI) m/z calcd for C14H12FO2S+ [M+H]+: 263.0537;
~
found: 263.0538.
127.4, 126.7, 126.4, 124.1, 123.3, 122.7 ppm. IR (ATR): u=1557,
1506, 1314, 1207, 1146, 1082, 684, 667, 651, 577 cmÀ 1. HRMS (ESI)
(Z)-[2-Bromo-1-(phenylsulfonyl)vinyl]benzene
4j:
Salt
5a
+
m/z calcd for C24H17O2S3 [M+H]+: 433.0385; found: 433.0388.
(115.3 mg, 0.2 mmol, 1.0 equiv.) and NEt4Br (64.5 mg, 0.2 mmol,
1.0 equiv.) were dissolved in CH2Cl2 (2 mL). The reaction mixture
was stirred at room temperature for 12 h and then directly
transferred to a pre-wetted column (hexanes). Analytically pure 4j
(58.8 mg, 181.9 μmol, 91%) was obtained as a colorless oil by
column chromatography (gradient hexanes!hexanes:EtOAc 8:2).
1H NMR (400 MHz, CDCl3): δ=7.84–7.79 (m, 2H), 7.60 (ddt, J=7.9,
7.0, 1.2 Hz, 1H), 7.49–7.44 (m, 2H), 7.41–7.36 (m, 1H), 7.34–7.29 (m,
2H), 7.25–7.21 (m, 2H), 7.01 (s, 1H) ppm. 13C NMR (101 MHz, CDCl3):
(Z)-5-(2-Chloro-2-phenylvinyl)-5H-dibenzo[b,d]thiophen-5-ium tri-
fluoromethanesulfonate 7: Salt 1b (102 mg, 235 μmol, 1.0 equiv.)
was dissolved in CH2Cl2 (2 mL), and HCl (0.18 mL, 2 M solution in
Et2O; 360 μmol, 1.53 equiv.) was added. After stirring the reaction
overnight the solvent was removed and diethyl ether (2×10 mL)
was added to wash the resulting oil. Salt 7 (53.1 mg, 112.7 μmol,
48%) was obtained as a white foam. 1H NMR (400 MHz, CD3CN): δ=
8.32 (d, J=8.6 Hz, 2H), 8.27 (d, J=8.1 Hz, 2H), 7.97 (t, J=8.2 Hz, 2H),
7.79 (t, J=7.2 Hz, 2H), 7.76–7.73 (m, 2H), 7.61–7.57 (m, 1H), 7.52–
7.47 (m, 2H), 6.84 (s, 1H) ppm. 13C NMR (101 MHz, CDCl3): δ=156.4,
δ=147.7, 139.8, 134.2, 133.9, 130.0, 129.7, 129.0, 129.0 (2 over-
13
~
lapped C signals), 128.4, 117.4 ppm. IR (neat): u=1576, 1445,
1319, 1146, 1082, 836, 718, 686, 533, 512 cmÀ 1. HRMS (ESI) m/z
calcd for C14H11BrNaO2S+ [M+Na]+: 344.9555; found: 344.9553.
141.0, 135.6, 134.3, 134.0, 132.6, 130.7, 130.2, 129.3, 128.7, 125.4,
1
~
122.1 (q, JC-F =322 Hz), 113.7 ppm. IR (ATR): u=1702, 1557, 1445,
1253, 1221, 1151, 1028, 924, 753, 635 cmÀ 1. HRMS (ESI) m/z calcd
(Z)-N,4-dimethyl-N-[2-phenyl-2-(phenylsulfonyl)vinyl]benzene sul-
fonamide 4k: A suspension of 5a (115.3 mg, 0.2 mmol, 1.0 equiv.),
Cs2CO3 (78.2 mg, 0.24 mmol, 1.2 equiv.) and N,4-dimethyl benzene-
sulfonamide (44.5 mg, 0.24 mmol, 1.2 equiv.) in CH2Cl2 (2 mL) was
stirred at r.t. for 12 h. and then directly transferred to a pre-wetted
column (hexanes). Compound 4k (71.0 mg 0.166 mmol, 83%) was
obtained as an off-white solid after purification by column
for C20H14ClS+ [MÀ OTf]+: 321.0499; found: 321.0494.
(E)-5-(2-Chloro-1-iodo-2-phenylvinyl)-5H-dibenzo[b,d]thio-phen-
5-ium trifluoromethanesulfonate 8: Iodine monochloride (45.8 mg,
282 μmol, 1.2 equiv.) was added to a solution of 1b (102 mg,
235 μmol, 1.0 equiv.) in CH2Cl2 (2 mL) and the reaction mixture
stirred at r.t. overnight. Subsequently, the solvent was removed
under reduced pressure and the residue washed with diethyl ether
(3×10 mL). Removal of the solvent using a filtration cannula
afforded 8 as a white solid, which was dried in vacuum (112.2 mg,
1
chromatography (gradient hexanes!hexanes:EtOAc 1:1). H NMR
(400 MHz, CDCl3): δ=8.38 (s, 1H), 7.74 (d, J=8.3 Hz, 2H), 7.56–7.47
(m, 3H), 7.40–7.33 (m, 4H), 7.28 (d, J=7.5 Hz, 1H), 7.16 (t, J=7.9 Hz,
2H), 6.93 (d, J=8.3 Hz, 2H), 2.47 (s, 3H), 2.46 (s, 3H) ppm. 13C NMR
(101 MHz, CD3CN): δ=145.3, 139.8, 136.7, 134.2, 133.0, 132.5, 130.4,
129.5, 129.3, 128.8, 128.3, 128.0, 127.5, 122.2, 34.8, 21.8 ppm. IR
0.188 mmol, 80%), m.p.: 255 C (with decomposition). 1H NMR
°
(400 MHz, CD3CN): δ=8.32 (dd, J=8.1, 1.5 Hz, 2H), 8.28 (dd, J=8.1,
1.6 Hz, 2H), 8.07–8.02 (m, 2H), 7.87–7.81 (m, 2H), 7.62 (dd, J=8.0,
1.7 Hz, 2H), 7.59–7.51 (m, 3H) ppm. 13C NMR (101 MHz, CDCl3): δ=
155.5, 141.8, 139.1, 136.5, 132.9, 132.9 (overlapped 13C signals),
~
(ATR): u=1630, 1357, 1287, 1170, 1141, 1082, 978, 943, 688,
+
545 cmÀ 1. HRMS (ESI) m/z calcd for C22H22NNaO4S2 [M+Na]+:
1
450.0804; found: 450.0794.
130.9, 130.0, 129.8, 129.6, 125.6, 122.1 (q, JC-F =321 Hz), 84.0 ppm.
~
IR (ATR): u=3086, 2360, 2268, 1253, 1221, 1156, 1025, 758, 673,
(Z)-5-[2-Phenyl-2-(phenylsulfonyl)vinyl]-5H-dibenzo[b,d]
phen-5-ium trifluoromethanesulfonate 5a: A Schlenk flask was
equipped with stirring bar and charged with 1b (1.01 g,
thio-
638 cmÀ 1. HRMS (ESI) m/z calcd for C20H13ClIS+ [MÀ OTf]+: 446.9466;
found: 446.9466.
a
2.32 mmol, 1.0 equiv.) and phenylsulfinic acid (330 mg, 2.32 mmol,
1.0 equiv.). The reactants were dissolved in a mixture of DCM
(10 mL) and t-BuOH (1 mL) and the reaction mixture was stirred at
room temperature for 12 h. After this, the solvents were evapo-
(E)-5-(1,2-Dibromo-2-phenylvinyl)-5H-dibenzo[b,d]thiophen-5-ium
trifluoromethanesulfonate 9: Bromine (37.6 mg, 12 μL, 235 μmol,
1.0 equiv.) was added to a solution of 1b (102 mg, 235 μmol,
1.0 equiv.) in CH2Cl2 (2 mL) and the reaction stirred at r.t. overnight.
Eur. J. Org. Chem. 2021, 1–12
www.eurjoc.org
7
© 2021 The Authors. European Journal of Organic Chemistry published
by Wiley-VCH GmbH
��
These are not the final page numbers!

Full Papers
doi.org/10.1002/ejoc.202100323
~
Removal of the solvent under reduced pressure afforded a solid
that was washed with Et2O (3×10 mL) and dried in vacuum.
Compound 9 (103.3 mg, 173.8 μmol, 74%) was obtained as a yellow
solid. 1H NMR (400 MHz, CD3CN): δ=8.38 (d, J=8.1 Hz, 2H), 8.31 (d,
J=8.6 Hz, 2H), 8.01 (t, J=7.7 Hz, 2H), 7.83 (t, J=8.4 Hz, 2H), 7.58
(dd, J=7.4, 2.3 Hz, 2H), 7.54–7.47 (m, 3H) ppm. 13C NMR (101 MHz,
(ATR): u=3091, 2950, 1710, 1325, 1258, 1159, 1121, 1068, 1028,
635 cmÀ 1. HRMS (ESI) m/z calcd for C26H18F3S+ [MÀ OTf]+: 419.1076;
found: 419.1079.
5-{3-([1,1’-Biphenyl]-2-yl)bicyclo[2.2.1]hepta-2,5-dien-2-yl}-5H-di-
benzo[b,d]thiophen-5-ium trifluoromethanesulfonate 13: Freshly
distilled cyclopentadiene (168.2 μL, 132.2 mg, 2.0 mmol, 5.0 equiv.)
was added to a solution of 1d (204 mg, 0.4 mmol, 1.0 equiv.) in
CDCl3): δ=144.4, 141.9, 138.7, 136.6, 132.8, 132.6, 129.9, 129.8,
1
~
129.5, 129.3, 125.6, 122.1 (q, JC-F =322 Hz), 108.2 ppm. IR (ATR): u=
°
MeCN (2 mL). The reaction mixture was heated at 100 C for 3 h
1445, 1258, 1224, 1156, 1025, 758, 697, 670, 635, 518 cmÀ 1. HRMS
(ESI) m/z calcd for C20H13Br2S+ [MÀ OTf]+: 442.9099; found:
442.9100.
under microwave irradiation. Subsequently, the solvents were
removed in vacuum and the solid thus obtained washed with Et2O
(3×30 mL). Compound 13 (119.9 mg, 207.9 μmol, 52%) was
1
(E)-5-{2-Chloro-1-iodo-2-[4-(trifluoromethyl)phenyl]vinyl}-5H-di-
benzo[b,d]thiophen-5-ium trifluoromethanesulfonate 10: Iodine
monochloride (268 mg, 1.65 mmol, 1.1 equiv.) was added in one
portion to a stirred solution of 1c (754 mg, 1.5 mmol, 1.0 equiv.) in
CH2Cl2 (10 mL) and the reaction mixture stirred at r.t. overnight.
Removal of the solvent under reduced pressure causes solidification
of a residue, which was washed with hexane (3×100 mL). After
drying in vacuum, salt 10 (917 mg, 1.38 mmol, 92%) was obtained
as a yellow solid. 1H NMR [400 MHz, (CD3)2CO]: δ=8.58 (d, J=
8.1 Hz, 2H), 8.54 (d, J=7.8 Hz, 2H), 8.12 (t, J=8.1 Hz, 2H), 7.93 (s,
6H) ppm. 19F NMR [377 MHz, (CD3)2CO]: δ=À 63.6, À 78.8 ppm. 13C
obtained as a brown solid. H NMR (400 MHz, CD3CN): δ=δ 8.29 (t,
J=9.4 Hz, 2H), 7.95–7.88 (m, 2H), 7.71 (d, J=8.7 Hz, 1H), 7.68–7.63
(m, 3H), 7.62–7.60 (m, 1H), 7.60–7.55 (m, 3H), 7.54–7.49 (m, 3H), 7.26
(d, J=8.0 Hz, 2H), 6.56–6.51 (m, 1H), 6.06–6.02 (m, 1H), 3.84–3.79
(m, 1H), 2.57–2.52 (m, 1H), 2.08–2.05 (m, 1H), 1.86–1.83 (m, 1H)
ppm. 13C NMR (101 MHz, CD3CN): δ=142.2, 141.7, 141.5, 141.1,
140.7, 135.4, 135.3, 132.5, 132.4, 132.1, 131.8, 131.7, 131.1, 130.0,
129.8, 129.6, 129.3, 129.2, 129.0, 128.8, 128.4, 128.0, 125.9, 125.5,
122.1 (q, 1JC-F =322 Hz), 72.0, 61.2, 51.1 ppm. IR (ATR): u=3730,
~
3628, 3594, 1539, 1260, 1151, 1028, 755, 673, 651 cmÀ 1. HRMS (ESI)
m/z calcd for C31H23S+ [MÀ OTf]+: 427.1515; found: 427.1518.
4
NMR [101 MHz, (CD3)2CO]: δ=152.3, 143.2 (q, JC-F =1.3 Hz), 141.9,
1,4-Dihydro-1,4-methanotriphenylene 14:
A
Schlenk flask
136.4, 132.8, 131.5, 130.9, 130.5, 130.0, 126.9 (q, 3JC-F =3.6 Hz), 125.6,
equipped with a stirring bar was charged with 13 (115.3 mg,
0.2 mmol, 1.0 equiv.), Cs2CO3 (71.7 mg, 0.22 mmol, 1.1 equiv.) and
[Ru(bipy)3]Cl2 ×6H2O (3 mg, 4.0 μmol, 2.0 mol%), purged three times
with nitrogen. After adding degassed MeCN (2 mL) the reaction
mixture was exposed to blue LED light irradiation (28 W) at r.t. for
16 h. Subsequently, the solvents were evaporated and the residue
124.6 (q, 1JC-F =272.6 Hz), 122.3 (q, 1JC-F =322.3 Hz), 87.6 ppm. IR
~
(ATR): u=3730, 3628, 1739, 1325, 1242, 1165, 1023, 670, 633,
512 cmÀ 1
.
HRMS (ESI) m/z calcd for C21H12ClF3IS+ [MÀ OTf]+:
514.9340; found: 514.9344.
(E)-5-{1,2-Dibromo-2-[4-(trifluoromethyl)phenyl]vinyl}-5H-dibenzo
[b,d]thiophen-5-ium trifluoromethanesulfonate 11: Bromine
(36.8 mg, 11.8 μL, 230 μmol, 1.0 equiv.) was added in one portion
to a solution of salt 1c (115.6 mg, 230 μmol, 1.0 equiv.) in CH2Cl2
(2 mL) and the reaction mixture thus obtained was stirred at room
temperature for 1 h. Removal of the solvent under reduced
pressure, afforded a solid, which was washed with Et2O (3×10 mL)
and pentane (10 mL). Salt 11 (120.3 mg, 181.6 μmol, 79%) was
charged into
a pre-wetted silica column (hexanes). Pure 14
(22.8 mg, 94 μmol, 47%) was obtained after column chromatog-
1
raphy (gradient hexanes!hexanes:CH2Cl2 4:1) as a white solid. H
NMR (400 MHz, CDCl3): δ=8.73 (d, J=8.1 Hz, 2H), 8.06 (d, J=7.6 Hz,
2H), 7.66–7.56 (m, 4H), 7.02 (s, 2H), 4.63 (s, 2H), 2.55 (d, J=6.6 Hz,
1H), 2.46 (d, J=6.6 Hz, 1H) ppm. 13C NMR (101 MHz, CDCl3): δ=
147.9, 143.8, 129.0, 128.7, 126.5, 125.3, 123.6, 123.5, 72.5, 49.2 ppm.
1
~
obtained as a white solid. H NMR (400 MHz, CD3CN): δ=8.37 (d,
IR (ATR): u=3060, 2980, 2928, 2862, 1506, 1298, 753, 720, 670,
+
J=7.7 Hz, 2H), 8.31 (dd, J=8.1, 0.9 Hz, 2H), 8.03 (td, J=7.7, 1.0 Hz,
660 cmÀ 1. HRMS (GCMS) m/z calcd for C19H14 [M]+: 242.1090;
2H), 7.86–7.80 (m, 4H), 7.76–7.71 (m, 2H) ppm. 19F NMR (377 MHz,
found: 242.1090. Analytical data are identical to the previously
CD3CN): δ=À 63.7, 79.3 ppm. 13C NMR (101 MHz, CDCl3): δ=142.5,
reported ones.[29]
3
142.1, 142.1, 136.8, 133.3, 133.0, 130.2, 130.0, 129.1, 127.1 (q, JC-F
=
(Z)-5-{2-([1,1’-Biphenyl]-2-yl)-2-(phenylsulfonyl)vinyl}-5H-dibenzo-
[b,d]thiophen-5-ium trifluoromethanesulfonate 15:
3.8 Hz, CF3), 125.9, 125.7, 122.1 (q, 1JC-F =321 Hz), 110.5 ppm. IR
A Schlenk
~
(ATR): u=3730, 1325, 1255, 1224, 1159, 1130, 1063, 1028, 761,
flask was equipped with a stirring bar and charged with 1d
(944.5 mg, 1.85 mmol, 1.0 equiv.) and phenylsulfinic acid (526 mg,
3.70 mmol, 2.0 equiv.). Subsequently, CH2Cl2 (16 mL) and t-BuOH
(2 mL) were added and the reaction mixture was stirred at r.t.
overnight. After this, the solvents were evaporated to a minimal
volume and Et2O (50 mL) was added, which causes precipitation of
crude 15. The latter was filtered off, washed with Et2O (30 mL) and
dried in vacuo to afford 15 (905.6 mg, 138.7 μmol, 75%) as a pale
635 cmÀ 1
.
HRMS (ESI) m/z calcd for C21H12Br2F3S+ [MÀ OTf]+:
512.8953; found: 512.8964.
5-{3-[4-(Trifluoromethyl)phenyl]bicyclo[2.2.1]hepta-2,5-dien-2-yl}-
5H-dibenzo[b,d]thiophen-5-ium trifluoromethane-sulfonate 12:
Freshly distilled cyclopentadiene (168.2 μL, 132.2 mg, 2.0 mmol,
5 equiv.) was added to a solution of 1c (200 mg, 0.40 mmol,
1.0 equiv.) in MeCN (2 mL), and the reaction mixture was heated to
1
°
100 C for 2 h under microwave irradiation. Subsequently, the
yellow solid. H NMR (400 MHz, CD3CN): δ=8.26 (d, J=7.9 Hz, 2H),
solvent was evaporated and the residue washed with n-hexane (2×
20 mL). The solid thus obtained was dried in vacuum affording 12
(152.4 mg, 0.268 mmol, 67%, a mixture of rotamers) as a pale green
8.06 (d, J=8.1 Hz, 2H), 7.98–7.90 (m, 3H), 7.86 (d, J=7.4 Hz, 2H),
7.79–7.75 (m, 2H), 7.74–7.69 (m, 2H), 7.49 (t, J=7.6 Hz, 1H), 7.36 (t,
J=7.7 Hz, 1H), 7.27–7.19 (m, 3H), 7.03 (t, J=7.8 Hz, 2H), 6.58 (d, J=
9.5 Hz, 2H), 6.52 (s, 1H) ppm. 13C NMR (101 MHz, CD3CN): δ=157.2,
143.8, 140.9, 139.8, 137.3, 136.2, 135.8, 132.9, 132.2, 131.9, 131.3,
1
solid. H NMR (400 MHz, CD3CN): δ=8.38 (dd, J=8.2, 4.0 Hz, 2H),
8.30 (d, J=8.6 Hz, 1H), 8.03–7.94 (m, 6H), 7.87–7.82 (m, 1H), 7.71–
7.60 (m, 2H), 6.97–6.92 (m, 1H), 6.24–6.20 (m, 1H), 4.25 (s, 1H), 2.77
(s, 1H), 2.22–2.15 (m, 1H), 1.99–1.96 (m, 1H) ppm. 19F NMR
(377 MHz, CD3CN): δ=À 63.3, À 79.3 ppm. 13C NMR (101 MHz,
130.9, 130.8, 130.6, 130.1, 129.9, 129.5, 129.2, 128.7, 128.6, 128.4,
1
~
125.4, 122.1 (q, JC-F =321 Hz) ppm. IR (ATR): u=3735, 3626, 3064,
3014, 1445, 1255, 1148, 1025, 635 cmÀ 1. HRMS (ESI) m/z calcd for
4
CD3CN): δ=178.7, 143.3, 141.3, 141.2, 140.9, 136.6 (q, JC-F =1.3 Hz),
C32H23O2S+ [MÀ OTf]+: 503.1134; found: 503.1137.
135.6, 135.5, 132.9 (q, 2JC-F =32.8 Hz), 132.68, 131.9, 131.3, 129.8,
129.44, 129.42, 129.42 (2 overlapped 13C signals), 129.0, 127.4, 127.1
(q, 3JC-F =3.8 Hz), 126.0, 125.6, 125.1 (q, 1JC-F =272.0 Hz), 122.1 (q,
1JC-F =320.2 Hz), 71.6, 60.0, 52.2 ppm (19 13C signals expected, 26
detected because of the hindered rotation of the DBT-unit). IR
9-(Phenylsulfonyl)phenanthrene 16: A Schlenk flask was equipped
with a stirring bar and charged with 15 (130.5 mg, 0.2 mmol,
1.0 equiv.), Cs2CO3 (71.7 mg, 0.22 mmol, 1.1 equiv.) and [Ru(bipy)3]
Cl2 ×6H2O (3 mg, 4.0 μmol, 2.0 mol%). Subsequently, CH3CN (2 mL)
Eur. J. Org. Chem. 2021, 1–12
www.eurjoc.org
8
© 2021 The Authors. European Journal of Organic Chemistry published
by Wiley-VCH GmbH
��
These are not the final page numbers!

Full Papers
doi.org/10.1002/ejoc.202100323
was added and the reaction mixture was exposed to blue LED light
1H), 3.91 (s, 3H), 3.85 (s, 3H), 3.81 (s, 3H), 3.24 (q, J=6.1 Hz, 2H), 2.97
(t, J=6.5 Hz, 2H), 2.38 (s, 3H), 1.12 (s, 21H) ppm. 13C NMR (75 MHz,
CDCl3): δ=151.2, 150.5, 147.8, 143.2, 136.5, 131.1, 129.5, 126.9,
121.2, 117.0, 102.5, 100.3, 61.2, 61.1, 61.0, 43.1, 28.8, 21.7, 18.8,
irradiation (28 W) at r.t. for 16 h. Subsequently, the solvents were
evaporated and the residue charged into a pre-wetted silica column
(hexanes). Pure 16 (36.9 mg, 115.8 μmol, 58%) was obtained by
column chromatography (gradient hexanes!hexanes:EtOAc 4:1)
as a pale-yellow solid. 1H NMR (400 MHz, CDCl3): δ=8.92 (s, 1H),
8.74–8.67 (m, 2H), 8.63 (d, J=9.0 Hz, 1H), 8.11 (d, J=8.5 Hz, 1H),
8.00 (d, J=7.3 Hz, 2H), 7.83 (t, J=8.4 Hz, 1H), 7.73 (t, J=7.1 Hz, 1H),
7.68 (t, J=7.0 Hz, 1H), 7.62–7.58 (m, 1H), 7.53 (t, J=7.3 Hz, 1H), 7.47
(t, J=7.4 Hz, 2H) ppm. 13C NMR (101 MHz, CDCl3): δ=141.7, 134.3,
133.2, 133.1, 132.9, 131.4, 130.9, 130.2, 129.4, 129.2, 127.8, 127.7,
127.5, 127.5 (2 overlapped 13C signals), 126.1, 125.5, 123.4,
~
11.4 ppm. IR (ATR): u=2940, 2890, 2863, 2151, 1461, 1411, 1397,
1336, 1158, 1093, 1020, 812, 662, 549 cmÀ 1. HRMS (ESI): m/z calcd
for C29H43BrNO5SSi+ [M+H]+: 624.1809; found: 624.1802.
4-Methyl-N-(2-{4,5,6-trimethoxy-2-[(triisopropylsilyl)ethynyl]-[1,1’-
biphenyl]-3-yl}ethyl)-benzenesulfonamide 23: To a solution of 22
(1.42 g, 2.27 mmol, 1.0 equiv.) and phenylboronic acid (555 mg,
4.55 mmol, 2.0 equiv.) in DME (9.5 mL), Na2CO3 (1.21 g, 11.4 mmol,
5.0 equiv.) and water (3.4 mL) were added. Finally, Pd(PPh3)2Cl2
(160 mg, 228 μmol, 10 mol%) was added to the suspension and the
~
122.9 ppm. IR (ATR): u=1447, 1322, 1151, 1082, 791, 753, 734, 686,
649, 566 cmÀ 1. HRMS (ESI) m/z calcd for C20H14NaO2S+ [M+Na]+:
341.0607; found: 341.0608. Analytical data are identical to the
previously reported ones.[30]
°
reaction mixture was stirred at 120 C for 26 h. under microwave
irradiation. After cooling to rt, the mixture was acidified with aq.
HCl (1 m) to pH=1. The aqueous layer was extracted with EtOAc
(3×40 mL), the combined organic phases were washed with brine
(50 mL), dried over MgSO4 and concentrated under reduced
pressure. Column chromatography (hexane/EtOAc, 10:1!3:1)
yielded 23 (1.39 g, 2.24 mmol, 99%) as a colorless oil. 1H NMR
(400 MHz, CDCl3): δ=7.60 (d, J=8.3 Hz, 2H), 7.38–7.24 (m, 5H), 7.20
(d, J=7.9 Hz, 2H), 4.88 (t, J=5.1 Hz, 1H), 3.93 (s, 3H), 3.87 (s, 3H),
3.54 (s, 3H), 3.25 (q, J=6.2 Hz, 2H), 3.02 (t, J=6.5 Hz, 1H), 2.38 (s,
3H), 0.88 (s, 21H) ppm. 13C NMR (101 MHz, CDCl3): δ=151.1, 150.5,
147.2, 143.0, 137.0, 136.5, 135.8, 130.2, 129.9, 129.5, 127.9, 127.3,
127.2, 119.0, 103.4, 98.6, 61.2, 61.1, 61.0, 43.5, 28.4, 21.6, 18.6,
N-(3-Bromo-2-iodo-4,5,6-trimethoxyphenethyl)-4-methyl-benze-
nesulfonamide 21: A solution of 20 (2.13 g, 5.83 mmol, 1.0 equiv.)
and NBS (1.04 g, 5.84 mmol, 1.0 equiv.) in CCl4 (20 mL) was stirred
°
at 50 C for 16 h in the dark. After cooling to rt, the reaction was
quenched with water (25 mL), and the aqueous phase was
extracted with CH2Cl2 (3×30 mL). The combined organic phases
were washed with sat. aq. Na2SO3 (30 mL) and brine (30 mL), dried
over Na2SO4 and concentrated in vacuo. Purification by column
chromatography (hexane/EtOAc, 7:3) gave N-(5-bromo-2,3,4-
trimethoxyphenethyl)-4-methylbenzene-sulfonamide
(2.31 g,
1
~
5.20 mmol, 89%) as an off-white solid. H NMR (300 MHz, CDCl3):
δ=7.67 (d, J=8.1 Hz, 2H), 7.27 (d, J=8.3 Hz, 2H), 6.88 (s, 1H), 4.61
(t, J=5.9 Hz, 1H), 3.92–3.77 (m, 9H), 3.17 (q, J=6.5 Hz, 2H), 2.67 (t,
J=6.8 Hz, 2H), 2.42 (s, 3H) ppm. 13C NMR (75 MHz, CDCl3): δ=151.6,
150.4, 147.5, 143.5, 137.1, 129.8, 128.3, 127.9, 127.2, 111.6, 61.1,
11.2 ppm. IR (ATR): u=2939, 2889, 2863, 2146, 1460, 1416, 1405,
1333, 1158, 1090, 1048, 880, 813, 661, 549 cmÀ 1. HRMS (ESI): m/z
calcd for C35H48NO5SSi+ [M+H]+: 622.3017; found: 622.3013.
N-(2-(2-ethynyl-4,5,6-trimethoxy-[1,1’-biphenyl]-3-yl)ethyl)-4-
methylbenzenesulfonamide 24: Under an atmosphere of nitrogen,
~
61.1, 61.1, 43.7, 30.3, 21.7 ppm. IR (ATR): u=2967, 2930, 2899, 2864,
a
Schlenk flask was charged with 23 (126 mg, 202.6 μmol,
2822, 1598, 1457, 1402, 1319, 1162, 1068, 1002, 807, 671, 554 cmÀ 1
.
1.0 equiv.), and dry THF (2 mL) was added. A solution of TBAF (1 M
HRMS (ESI): m/z calcd for C18H23BrNO5S+ [M+H]+: 444.0475; found:
444.0477. To a solution of this compound (2.0 g, 4.50 mmol,
1.0 equiv.) in acetonitrile (19 mL) was added NIS (2.53 g,
11.25 mmol, 2.5 equiv.) and TFA (1.283 g, 0.86 mL, 11.25 mmol,
°
in THF, 0.26 mL, 0.26 mmol, 1.3 equiv.) was added at 0 C and the
reaction mixture was stirred at rt for 2 h. The reaction was
quenched with sat. aq. NH4Cl (6 mL), and the aqueous phase was
extracted with EtOAc (3×15 mL). The combined organic phases
were washed with brine (20 mL), dried over MgSO4 and concen-
trated under reduced pressure. The crude product was purified by
flash chromatography on silica (hexane/EtOAc, 20:1!3:1) to
°
2.5 equiv.). The reaction mixture was stirred at 110 C for 16 h under
microwave irradiation. The reaction was quenched with sat. aq.
Na2SO3 (50 mL) at rt, and the aqueous layer was extracted with
DCM (3×30 mL). The combined organic phases were washed with
brine (40 mL), dried over MgSO4 and concentrated under reduced
pressure. The residue was purified by column chromatography
(hexane/EtOAc, 9:1!3:1). Product 21 (1.94 g, 3.40 mmol, 76%)
deliver 24 (89 mg, 0.19 mmol, 94%) as a colorless solid, m.p.: 154–
1
°
155 C. H NMR (400 MHz, CDCl3): δ=7.66 (d, J=8.3 Hz, 2H), 7.45–
7.29 (m, 5H), 7.23 (d, J=8.1 Hz, 2H), 4.83 (t, J=5.4 Hz, 1H), 3.93 (s,
3H), 3.87 (s, 3H), 3.53 (s, 3H), 3.25 (q, J=6.7 Hz, 2H), 3.03–2.97 (m,
3H), 2.39 (s, 3H) ppm. 13C NMR (101 MHz, CDCl3): δ=151.2, 150.5,
147.6, 143.1, 137.2, 136.2, 135.8, 130.4, 130.2, 129.6, 127.8, 127.6,
127.2, 117.5, 84.3, 80.5, 61.3, 61.0, 61.0, 43.4, 28.6, 21.7 ppm. IR
1
was obtained as a brownish oil. H NMR (300 MHz, CDCl3): δ=7.59
(d, J=8.0 Hz, 2H), 7.19 (d, J=8.0 Hz, 2H), 4.81 (t, J=5.4 Hz, 1H),
3.93–3.81 (m, 9H), 3.19 (q, J=6.4 Hz, 2H), 3.04 (t, J=6.8 Hz, 2H), 2.40
(s, 3H) ppm. 13C NMR (75 MHz, CDCl3): δ=151.1, 150.7, 147.2, 143.4,
136.8, 132.5, 129.7, 127.0, 121.7, 101.6, 61.3, 61.0, 60.9, 42.3, 36.9,
~
(ATR): u=2936, 2871, 2836, 1460, 1415, 1404, 1327, 1155, 1103,
1020, 814, 705, 661, 548 cmÀ 1
HRMS (ESI): m/z calcd for
C26H28NO5S+ [M+H]+: 466.1683; found: 466.1685.
.
~
21.7 ppm. IR (ATR): u=2936, 2861, 1735, 1458, 1398, 1386, 1325,
1154, 1094, 1046, 999, 813, 662, 548 cmÀ 1. HRMS (ESI): m/z calcd for
C18H22BrINO5S+ [M+H]+: 569.9441; found: 569.9444.
Compound 25: In Schlenk flask, dibenzothiophene-S-oxide
a
(23.5 mg, 0.117 mmol, 1.0 equiv.) was dissolved in CH2Cl2 (1 mL).
Tf2O (36.4 mg, 21.7 μL, 0.129 mmol, 1.10 equiv.) was added to the
N-{3-Bromo-4,5,6-trimethoxy-2-[(triisopropylsilyl)
phenethyl}-4-methylbenzene-sulfonamide 22: To
(11 mL) solution containing 21 (1.90 g, 3.33 mmol, 1.0 equiv.) and
NEt3 (4.6 mL), Pd(PPh3)2Cl2 (233 mg, 331.9 μmol, 10 mol%), CuI
(126 mg, 0.662 mmol, 0.2 equiv.) and TIPS- acetylene (3,65 g,
4.49 mL, 20.0 mmol, 6.01 equiv.) were added, and the mixture was
ethynyl]
dry THF
a
°
solution at À 50 C, and the red suspension obtained was stirred for
30 min at this temperature. Compound 24 (60.0 mg, 0.129 mmol,
°
1.1 equiv.) was added at À 60 C, and the reaction mixture was
°
allowed to warm up to À 20 C overnight. The solvent was then
removed in vacuo and the residue was washed with dry Et2O (2×
2 mL) in an ultrasonic bath. Purification by column chromatography
(CH2Cl2/acetone, 9:1!1:1) delivered 25 (38.0 mg, 47.6 μmol, 41%)
°
stirred at 90 C for 60 h under microwave irradiation. The
suspension thus obtained was filtered through a pad of silica gel
and eluted with CH2Cl2 (60 mL). The filtrate was concentrated in
vacuo and the residue purified by column chromatography
(hexane/EtOAc, 10%!30%). Sulfonamide 22 (1.52 g, 2.43 mmol,
1
as a brown solid. H NMR (400 MHz, CDCl3): δ=8.33 (d, J=8.1 Hz,
2H), 8.00 (d, J=7.9 Hz, 2H), 7.94 (d, J=8.4 Hz, 2H), 7.79 (t, J=7.6 Hz,
2H), 7.67 (t, J=7.7 Hz, 2H), 7.39 (d, J=8.2 Hz, 2H), 7.15–7.05 (m, 4H),
6.87 (t, J=6.8 Hz, 1H), 4.49 (s, 1H), 3.91 (s, 3H), 3.87 (t, J=6.5 Hz,
2H), 3.79 (s, 3H), 3.50 (s, 3H), 2.93 (t, J=6.5 Hz, 2H), 2.44 (s, 3H) ppm.
1
73%) was obtained as a colorless solid. H NMR (300 MHz, CDCl3):
δ=7.51 (d, J=8.1 Hz, 2H), 7.14 (d, J=8.0 Hz, 2H), 4.75 (t, J=5.2 Hz,
Eur. J. Org. Chem. 2021, 1–12
www.eurjoc.org
9
© 2021 The Authors. European Journal of Organic Chemistry published
by Wiley-VCH GmbH
��
These are not the final page numbers!

Full Papers
doi.org/10.1002/ejoc.202100323
13C NMR (101 MHz, CDCl3): δ=151.4, 150.6, 150.2, 149.3, 146.1,
139.0, 135.4, 134.2, 133.3, 131.8, 130.5, 130.0, 129.9, 128.8, 128.6,
127.7, 127.6, 125.8, 123.6, 116.0, 61.3, 61.14, 61.11, 45.9, 21.9,
2016; b) Hypervalent Iodine Chemistry, V. V. Zhdankin; John Wiley &Sons,
Ltd, 2014.
[3] For recent reviews see: a) A. Boelke, P. Finkbeiner, B. J. Nachtsheim,
Beilstein J. Org. Chem. 2018, 14, 1263–1280; b) A. Yoshimura, V. V.
Zhdankin, Chem. Rev. 2016,116, 3328–3435; c) J. P. Brand, J. Waser,
Chem. Soc. Rev. 2012, 41, 4165–4179.
[4] F. M. Beringer, S. A. Galton, J. Org. Chem. 1965, 30, 1930–1934.
[5] M. Ochiai, Y. Masaki, M. Shiro, J. Org. Chem. 1991, 56, 5511–5513.
[6] V. V. Zhdankin, C. J. Kuehl, A. P. Krasutsky, J. T. Bolz, A. J. Simonsen, J.
Org. Chem. 1996, 61, 6547–6551.
[7] a) M. Ochiai, M. Kunishima, Y. Nagao, K. Fuji, M. Shiro, E. Fujita, J. Am.
Chem. Soc. 1986, 108, 8281–8283; b) M. Ochiai, T. Ito, Y. Takaoka, Y.
Masaki, M. Kunishima, S. Tani, Y. Nagao, J. Chem. Soc. Chem. Commun.
1990, 118–119.
[8] M. D. Bachi, N. Bar-Ner, C. M. Crittell, P. J. Stang, B. L. Williamson, J. Org.
Chem. 1991, 56, 3912–3915.
[9] a) D. Fernández-González, J. P. Brand, J. Waser, Chem. Eur. J. 2010, 16,
9457–9461; b) D. Fernández-González, J. P. Brand, R. Mondière, J. Waser,
Adv. Synth. Catal. 2013, 355, 1631–1639; c) R. Frei, J. Waser, J. Am. Chem.
Soc. 2013, 135, 9620–9623; d) R. Frei, M. D. Wodrich, D. P. Hari, P. A.
Borin, C. Chauvier, J. Waser, J. Am. Chem. Soc. 2014, 136, 16563–16573;
e) C. C. Chen, J. Waser, Chem. Commun. 2014, 50, 12923–12926.
[10] a) F. M. Beringer, S. A. Galton, J. Org. Chem. 1965, 30, 1930–1934; b) M.
Ochiai, Y. Kitagawa, M. Toyonari, K. Uemura, K. Oshima, M. Shiro, J. Org.
Chem. 1997, 62, 8001–8008; c) L. I. Dixon, M. A. Carroll, T. J. Gregson,
G. J. Ellames, R. W. Harrington, W. Clegg, Eur. J. Org. Chem. 2013, 12,
2334–2345.
[11] a) E. Kotali, A. Varvoglis, A. Bozopoulos, J. Chem. Soc. Perkin Trans. 1
1989, 827–832; b) G. Maas, M. Regitz, U. Moll, R. Rahm, F. Krebs, R.
Hector, P. J. Stang, C. M. Crittell, B. L. Williamson, Tetrahedron 1992, 48,
3527–3540; c) P. J. Stang, T. Blume, V. V. Zhdankin, Synthesis 1993, 35–
36; d) P. Murch, A. M. Arif, P. J. Stang, J. Org. Chem. 1997, 62, 5959–5965.
[12] See ref. 2b, Chapter 7, page 425: “The vast majority of organic λ3-
iodanes lack thermal stability and some of them are explosive”.
[13] a) B. Waldecker, K. Kafuta, M. Alcarazo, Org. Synth. 2019, 96, 258–276;
b) B. Waldecker, F. Kraft, C. Golz, M. Alcarazo, Angew. Chem. Int. Ed.
2018, 57, 12538–12542; Angew. Chem. 2018, 130, 12718–12722.
[14] T. Kitamura, T. Tanaka, H. Taniguchi, P. J. Stang, J. Chem. Soc. Perkin
Trans. 1 1991, 2892–2893.
~
21.0 ppm (triflate-carbon not observed). IR (ATR): u=2939, 1597,
1448, 1402, 1332, 1257, 1232, 1156, 1028, 813, 751, 708, 635 cmÀ 1
.
+
HRMS (ESI): m/z calcd for C38H34NO5S2 [MÀ OTf]+: 648.1873; found:
648.1874.
1,2,3-Trimethoxy-6-tosyl-5,6-dihydro-4H-dibenzo[de,g] quinoline
26 and 4,5,6-Trimethoxy-1-tosyl-2,3-dihydro-1H-azuleno[1,2,3-ij]
isoquinoline 27: A flame-dried Schlenk flask was charged with 25
(34.9 mg, 43.7 μmol, 1.0 equiv.), Cs2CO3 (19.9 mg, 61.2 μmol,
1.4 equiv.) and [Ru(bpy)3]Cl2 ·6H2O (0.97 mg, 1.3 μmol, 3 mol%).
CH3CN (1.0 mL) was added, and the solution was degassed with
nitrogen for 5 min. The reaction mixture was irradiated with
vigorous stirring at r.t. with blue LEDs (28 W) for 22 h. Subsequently,
the solvent was removed in vacuo and the residue was purified by
flash chromatography (hexane!hexane:EtOAc, 3:1) to give 26
(2.1 mg, 4.5 μmol, 10%) as a green solid and 27 (3.2 mg, 6.9 μmol,
16%) as a green-blue solid.
26: 1H NMR (400 MHz, CDCl3): δ=9.53–9.47 (m, 1H), 8.00 (s, 1H),
7.90–7.84 (m, 1H), 7.64–7.54 (m, 2H), 7.45 (d, J=8.3 Hz, 2H), 7.04 (d,
J=8.1 Hz, 2H), 4.07 (t, J=6.1 Hz, 2H), 4.02 (s, 3H), 3.96 (s, 3H), 3.79
(s, 3H), 2.81 (t, J=6.1 Hz, 2H), 2.28 (s, 3H) ppm. 13C NMR (101 MHz,
CDCl3): δ=151.4, 149.2, 146.1, 143.6, 137.9, 131.8, 131.0, 129.5,
128.9, 128.4, 127.2, 127.1, 126.8, 126.7, 122.2 (2 overlapped 13C
~
signals), 119.9, 61.3, 60.8, 60.5, 44.5, 22.3, 21.5 ppm. IR (ATR): u=
2932, 2850, 1737, 1596, 1455, 1386, 1338, 1161, 1090, 1014, 721,
662, 567, 545 cmÀ 1. HRMS (ESI): m/z calcd for C26H26NO5S+ [M+H]+:
464.1526; found: 464.1527.
1
27: H NMR (600 MHz, CDCl3): δ=8.71 (dd, J=8.6, 1.0 Hz, 1H), 8.37
(dt, J=11.1, 0.9 Hz, 1H), 7.36–7.33 (m, 2H), 7.18 (ddt, J=11.0, 8.4,
1.0 Hz, 1H), 7.02–7.00 (m, 2H), 6.99 (ddt, J=11.1, 8.5, 0.8 Hz, 1H),
6.88 (ddd, J=11.1, 8.4, 0.8 Hz, 1H), 4.15 (s, 3H), 4.00 (t, J=5.9 Hz,
2H), 3.93 (s, 3H), 3.77 (s, 3H), 2.43 (t, J=5.9 Hz, 2H), 2.28 (s, 3H). 13C
NMR (126 MHz, CDCl3): δ=151.4, 149.5, 143.8, 142.6, 138.4, 136.9,
135.8, 134.3, 132.8, 131.2, 130.1, 129.5, 127.5, 126.3, 124.0, 120.9,
[15] Deposition Numbers 2068276 (2f), 2068277 (2j), 2068278 (3e), 2068279
(5a), 2068280 (6), 2068281 (8), 2068282 (10), 2068283 (11), 2068284
(11Br), 2068285 (24), and 2068286 (28) contain the supplementary
crystallographic data for this paper. These data are provided free of
charge by the joint Cambridge Crystallographic Data Centre and
Fachinformationszentrum Karlsruhe Access Structures service
www.ccdc.cam.ac.uk/structures.
~
115.0, 113.6, 61.7, 61.3, 60.7, 47.9, 21.6, 19.8. IR (ATR): u=2935,
2840, 1604, 1391, 1350, 1290, 1159, 1139, 1044, 1006, 708, 660,
.
543 cmÀ 1 HRMS (ESI): m/z calcd for C26H26NO5S+ [M+H]+:
464.1531; found: 464.1526.
[16] R. R. Tykwinski, B. L. Williamson, D. R. Fischer, P. J. Stang, A. M. Arif, J.
Org. Chem. 1993, 58, 5235–5237.
[17] a) S.-i. Watanabe, K. Yamamoto, Y. Itagaki, T. Iwamura, T. Iwama, T.
Kataoka, G. Tanabe, O. Muraoka, J. Chem. Soc. Perkin Trans. 1 2001, 239–
247; b) S.-i. Watanabe, E. Mori, H. Nagai, T. Iwamura, T. Iwama, T.
Kataoka, J. Org. Chem. 2000, 65, 8893–8898; c) S.-i. Watanabe, E. Mori, H.
Nagai, T. Kataoka, Synlett 2000, 49–52; d) M. Ochiai, Y. Kitagawa, M.
Toyonari, K. Uemura, K. Oshima, M. Shiro, J. Org. Chem. 1997, 62, 8001–
8008.
[18] See for example: a) X. Zeng, S. Liu, Y. Yang, Y. Yang, G. B. Hammond, B.
Xu, Chem. 2020, 6, 1018–1031; b) J. Chen, J. Li, M. B. Plutschack, F.
Berger, T. Ritter, Angew. Chem. Int. Ed. 2020, 59, 5616–5620; Angew.
Chem. 2020, 132, 5665–5669; c) M. H. Aukland, F. J. T. Talbot, J. A.
Fernández-Salas, M. Ball, A. P. Pulis, D. J. Procter, Angew. Chem. Int. Ed.
2018, 57, 9785–9789; Angew. Chem. 2018, 130, 9933–9937; d) S. Desrat,
C. Remeur, C. Gény, G. Rivière, C. Colas, V. Dumontet, N. Birlirakis, B. I.
Iorga, F. Roussi, Chem. Commun. 2014, 50, 8593–8596; e) D. Chen, Y.
Cao, Z. Yuan, H. Cai, R. Zheng, L. Kong, G. Zhu, J. Org. Chem. 2011, 76,
4071–4074; f) T. B. Poulsen, G. Dickmeiss, J. Overgaard, K. A. Jørgensen,
Angew. Chem. Int. Ed. 2008, 47, 4687–4690; Angew. Chem. 2008, 120,
4765–4768; g) E. Negishi, A. Alimardanov, C. Xu, Org. Lett. 2000, 2, 65–
67.
Acknowledgements
Financial support from the Deutsche Forschungsgemeinschaft
(INST 186/1237-1 and INST 186/1324-1) and the European
Research Council (ERC CoG 771295) is gratefully acknowledged.
Open access funding enabled and organized by Projekt DEAL.
Conflict of Interest
The authors declare no conflict of interest.
Keywords: Addition reactions
alkynylation · Sulfonium salts · Vinyl sulfones
·
Diynes
·
Electrophilic
[19] M. Shimitzu, Y. Takeda, T. Hiyama, Chem. Lett. 2008, 37, 1304–1305.
[20] For recent reviews on the topic see: a) Á. Péter, G. J. P. Perry, D. J.
Procter, Adv. Synth. Catal. 2020, 362, 2135–2142; b) S. Kozhushkov, M.
Alcarazo, Eur. J. Inorg. Chem. 2020, 2486–2500; c) D. Kaiser, I. Klose, R.
Oost, J. Neuhaus, N. Maulide, Chem. Rev. 2019, 119, 8701–8780.
[21] M. H. Aukland, M. Šiaučiulis, A. West, G. J. P. Perry, D. J. Procter, Nat.
Catal. 2020, 3, 163–169.
[1] V. V. Zhdankin, P. J. Stang, Tetrahedron 1998, 54, 10927–10966.
[2] For a general monographies in I(III) chemistry see: a) T. Wirth, Topics in
Current Chemistry, Vol. 373, Springer International Publishing, Chamm,
Eur. J. Org. Chem. 2021, 1–12
www.eurjoc.org
10
© 2021 The Authors. European Journal of Organic Chemistry published
by Wiley-VCH GmbH
��
These are not the final page numbers!

Full Papers
doi.org/10.1002/ejoc.202100323
[22] For a similar cyclization see: S. Karreman, S. B. H. Karnbrock, S. Kolle, C.
[29] M. Mansø, L. Fernandez, Z. Wang, K. Moth-Poulsen, M. B. Nielsen,
Golz, M. Alcarazo, Org. Lett. 2021, 23, 1991–1995.
Molecules 2020, 25, 322.
[23] E. M. K. Wijeratnea, A. A. L. Gunatilaka, D. G. I. Kingston, R. C. Halti-
wanger, D. S. Eggleston, Tetrahedron 1995, 51, 7877–7882.
[24] A. Sari, A. I. Gray, G. Sariyar, Nat. Prod. Res. 2004, 18, 265–268.
[25] B. Liu, L. Jian, G. Chen, X. Song, C. Han, J. Wang, Chem. Nat. Compd.
2014, 49, 1172–1174.
[30] Y. H. Kim, H. Lee, Y. J. Kim, B. T. Kim, J.-N. Heo, J. Org. Chem. 2008, 73,
495–501.
[26] Aporphine Alkaloids. In: Natural Compounds. S. S. Azimova, M. S. Yunusov
(Eds), Springer, New York, 2013.
[27] C.-W. Chien, C. Shi, C.-F. Lin, I. Ojima, Tetrahedron 2011, 67, 6513–6523.
[28] K. S. Feldman, T. D. Cutarelli, J. Am. Chem. Soc. 2002, 124, 11600–11601.
Manuscript received: March 16, 2021
Revised manuscript received: April 14, 2021
Accepted manuscript online: April 15, 2021
Eur. J. Org. Chem. 2021, 1–12
www.eurjoc.org
11
© 2021 The Authors. European Journal of Organic Chemistry published
by Wiley-VCH GmbH
��
These are not the final page numbers!

FULL PAPERS
Dr. K. Kafuta, C. J. Rugen, T.
Heilmann, T. Liu, Dr. C. Golz,
Prof. Dr. M. Alcarazo*
1 – 12
Reactivity of 5-(Alkynyl)
dibenzothiophenium Salts:
Synthesis of Diynes, Vinyl
Sulfones, and Phenanthrenes
The synthetic potential of 5-(alkynyl)
benzothiophenium salts is further
evaluated. In addition to their reactiv-
ity as electrophilic alkynylation
additions to the CÀ C triple bond. The
products thus obtained can be used
for the synthesis of Z-vinyl sulfones
and 9,10-substituted phenanthrenes.
reagents, they undergo regioselective